Modal Dialog resizing

In Photoshop (I'm using the latest 22.4.1) cs.resizeContent doesn't do anything to me. I have an initial Geometry:

            <UI>
               <Type>ModalDialog</Type>
               <Menu>My Extension</Menu>
               <Geometry>
                  <Size>
                     <Height>600</Height>
                     <Width>800</Width>
                  </Size>
               </Geometry>
            </UI>

Should I wait for some events before calling such method? I'd like to make my ModalDialog as largest as possible. It would be nice if the user could also resize it.

Any example I can get inspired from? Thanks!